Define structure of the information about subnetwork #180
Description
Summary
Information about subnetwork is stored and trasmitted between NeoFS components. It must have strict binary format and support
feature extensibility without losing backward compatibility. NeoFS API protocol messages are perfectly suited for this.
Task
Define SubnetInfo message structure (it can be placed in dedicated subnet package). It must consist of ID and owner ID (refs.OwnerID) fields. ID should be a separate type in order to describe its binary and string format. For now it should carry single numerical field. Both fields are required.
Note
ID definition is also required in #179.